The aims of this study are (1) to test the anti-amyloid 10H3 antibody with Alzheimer's disease for its ability to image amyloid infiltration of cerebral vessels using single photon emission CT (SPECT) and (2) to examine the relationships between disease severity and intensity and distribution of amyloid deposition in the brain. The hypothesis is that the specificity of the amyloid antibody is sufficient to produce images of amyloid deposition in the brain.